Generally, a microbial fuel cell (MFC) is a device that converts chemical energy to electrical energy by the action of microorganisms. The microbial fuel cell (MFC), which is also termed as bio-batteries or biological fuel cells, utilize catalysts such as bacteria for oxidizing organic and inorganic matters to generate an electrical current. The electrons produced by the bacteria through oxidation of the organic and inorganic matters are transferred to an anode or a negative pole, and then flows by a conductive material including a resistance to a cathode or a positive pole. By convection, a positive current from the positive pole is established to the negative pole, opposite of an electron current. Bio-batteries are constructed in different configurations with different materials.
The limited output of electrical power is a major limitation faced by the MFC. One of the main factors affecting the existing MFC is the type of materials used for the electrodes, type of catalyst and fuels. Habermnan and Pommer have constructed a biological cell with cobalt oxide and alloy of molybdenum/vanadium electrode, hydrogen sulfide as fuel generating output power of 150 mA/m2. Capodaglio et al. utilized municipal waste as a fuel, and the carbon cloth with a steel belt was used as the anode, generating output power of 13 mW/m3. In general, bio batteries with several different fuels and anodes were made so far, generated low output power of 30-150 mW/m2.
Although different materials have been utilized for making anodes and cathodes, the existing known materials implemented in the electrodes still provide lower power densities, and generating low electrical current when compared to the other existing fuel cells.
Therefore, there is a need in an art for increasing power density, and providing stable power supply using an economical fuel and generally available microorganism in the microbial fuel cells. There is also a need for simple, efficient, economical and biocompatible construction in the microbial fuel cell.